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C2 function question

I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf
What was the original question?
Original post by indignation
I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf


Would you mind posting the full question? :colondollar:

Edit: It looks like you've posted everything, sorry. See below.
(edited 8 years ago)
Original post by indignation

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x

It looks like it wants you to put

(2x^3/2 - 3x^-3/2)^2 +5 = 5

But without the full question its hard to tell (as others have said)
Original post by indignation
I don't understand the answer to this, or how to even get there. I expanded/simplified it first, but still get the wrong answer. help. pls.

f(x) = (2x^3/2 - 3x^-3/2)^2 +5
f(x) = 5

Find the value of x to 3 sf


No need to expand
if f(x) = 5 then (2x^3/2 - 3x^-3/2)^2 = 0
Solving for x from there should be straightforward

Posted from TSR Mobile
(edited 8 years ago)
Reply 5
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Original post by Quantum Confinement
It looks like it wants you to put

(2x^3/2 - 3x^-3/2)^2 +5 = 5

But without the full question its hard to tell (as others have said)


yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?
Original post by indignation
yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?

g(x)2=0g(x)^2 = 0 if and only if g(x)=0g(x) = 0.
Reply 7
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ohhh, that makes a lot of sense
Original post by Smaug123
g(x)2=0g(x)^2 = 0 if and only if g(x)=0g(x) = 0.
Original post by indignation
yes that is right, but how do you correctly simplify the (2x^3/2 - 3x^-3/2)^2?

Square root both sides then take it from there
(edited 8 years ago)

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